test_streamwarp.py: Little-endian buffer not supported on big-endian compiler

[nteodosio]

Description

Tests from test_streamwarp.py fail in big endian architectures. On s390x:

=================================== FAILURES ===================================
_______________________________ test_bundlewarp ________________________________

    def test_bundlewarp():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)

dipy/align/tests/test_streamwarp.py:15: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler

dipy/tracking/streamlinespeed.pyx:338: ValueError
_________________________ test_bundlewarp_vector_filed _________________________

    def test_bundlewarp_vector_filed():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)

dipy/align/tests/test_streamwarp.py:38: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler

dipy/tracking/streamlinespeed.pyx:338: ValueError
__________________________ test_bundle_shape_profile ___________________________

    def test_bundle_shape_profile():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)

dipy/align/tests/test_streamwarp.py:62: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler

dipy/tracking/streamlinespeed.pyx:338: ValueError

I suppose a adding big endian checks are desired, but for what it's worth downstream I proposed the attached patch to simply skip the tests on big endian architectures.
skip-streamwarp-test-in-big-endian.txt

Way to reproduce

• Operating system and version: Ubuntu 23.10.
• Python version: 3.11.
• dipy version: 1.7.0
• dependency version (numpy, scipy, nibabel, h5py, cvxpy, fury)
  • import numpy; 1.24.2
  • import scipy; 1:10.1
  • import nibabel; 5.1.0
  • import h5py; 3.7.0
  • import cvxpy;
  • import fury;

[skoudoro]

thank you for this report @nteodosio.

For now, we will apply your patch but we will try to figure out why it is failing on big endian.

What surprise me is set_number_of_points is used everywhere, so I wonder why it failed only for this test

[penguinpee]

I'm still seeing those endianness errors in 1.8.0:

Test failures on `s390x`

=================================== FAILURES ===================================
_______________________________ test_bundlewarp ________________________________
    def test_bundlewarp():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)
dipy/align/tests/test_streamwarp.py:15: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler
streamlinespeed.pyx:338: ValueError
_________________________ test_bundlewarp_vector_filed _________________________
    def test_bundlewarp_vector_filed():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)
dipy/align/tests/test_streamwarp.py:38: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler
streamlinespeed.pyx:338: ValueError
__________________________ test_bundle_shape_profile ___________________________
    def test_bundle_shape_profile():
    
        cingulum_bundles = two_cingulum_bundles()
    
        cb1 = Streamlines(cingulum_bundles[0])
>       cb1 = set_number_of_points(cb1, 20)
dipy/align/tests/test_streamwarp.py:62: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
>   ???
E   ValueError: Little-endian buffer not supported on big-endian compiler
streamlinespeed.pyx:338: ValueError
______________________________ test_sphere_dtypes ______________________________
    def test_sphere_dtypes():
        for sphere_name, sphere_path in SPHERE_FILES.items():
            sphere_data = np.load(sphere_path)
>           npt.assert_equal(sphere_data['vertices'].dtype, np.float64)
E           AssertionError: 
E           Items are not equal:
E            ACTUAL: dtype('<f8')
E            DESIRED: <class 'numpy.float64'>
dipy/data/tests/test_data.py:8: AssertionError
=============================== warnings summary ===============================
../../BUILDROOT/python-dipy-1.8.0-5.fc41.s390x/usr/lib64/python3.12/site-packages/dipy/viz/__init__.py:22
  /builddir/build/BUILDROOT/python-dipy-1.8.0-5.fc41.s390x/usr/lib64/python3.12/site-packages/dipy/viz/__init__.py:22: UserWarning: You do not have FURY installed. Therefore, 3D visualization functions will not work for you. Please install or upgrade FURY using pip install -U furyFor detailed installation instructions visit: https://fury.gl/
    warnings.warn(
dipy/align/tests/test_reslice.py: 7 warnings
dipy/denoise/tests/test_gibbs.py: 18 warnings
dipy/workflows/tests/test_denoise.py: 1 warning
  /usr/lib64/python3.12/multiprocessing/popen_fork.py:66: DeprecationWarning: This process (pid=9419) is multi-threaded, use of fork() may lead to deadlocks in the child.
    self.pid = os.fork()
dipy/workflows/tests/test_tracking.py::test_particle_filtering_tracking_workflows
  /builddir/build/BUILD/dipy-1.8.0/dipy/workflows/tests/test_tracking.py:73: RuntimeWarning: invalid value encountered in cast
    save_nifti(path, arr.astype(np.uint8), affine)
-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================== short test summary info ============================
FAILED dipy/align/tests/test_streamwarp.py::test_bundlewarp - ValueError: Lit...
FAILED dipy/align/tests/test_streamwarp.py::test_bundlewarp_vector_filed - Va...
FAILED dipy/align/tests/test_streamwarp.py::test_bundle_shape_profile - Value...
FAILED dipy/data/tests/test_data.py::test_sphere_dtypes - AssertionError: 
= 4 failed, 784 passed, 81 skipped, 16 deselected, 28 warnings in 881.67s (0:14:41) =

Let me know if you prefer a new issue. But this looks pretty much like what OP reported.

[penguinpee]

I just updated the package in Fedora to 1.9.0. Unfortunately tests still fail on s390x.